Hydraulic booster mechanism



.1.A o. ALMEN HYDRAULIC "BOOSTER MECHANISM- Filed Dec. 3l, 1928 lidar.8, 1932 UNITED @STATES PATENT OFFICE v J' 0R17 ALME'N, 0F ROYAL OAK,MICHIGAN, ASSIGNOR T0 GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT,MICHIGAN, A. CORPORATTON'-, 0F DELAWARE HYDRAULIC Boos'rEn MECHANISMApplication led December 31, 1928. Serial No. 329,621.

VThis invention'relates to a steering mechanism and has been' designedmore particularly for the actuationby power of the steery ing wheelsofvehicles. Its use in other relations will, nevertheless, be obvious.

An objectof the invention is to provide fluid pressurem means to eiiectthe steering. As av further object, the invention aims to so relate theconventional steering wheel to the novel huid pressure means that therotation of the steering wheel may render the iiuid pressure meansactive. Another object is to so arrange themechanism that the powermeans shall continue active only so long as -the steering wheel is beingturned. Other objects such as etliciency, and simplicity inconstruction, .will be understood from a reading of the followingdescription.

nthe drawings accompanying this description:

liigure 1 is a side elevation of the novel mechanism associated. with aside frame inember of .the vehicle chassis.

Figure 2 is a longitudinal section through the power cylinder.

iif'fferring by reference characters to the drawings, numeral 3 is theusual steering wheel carried by a steering post 5. This steering post 5is rotatably mounted in a.

bracket 7 securely fastened as by fastening 'means at 9. The post 5 isprovided with a worm 13 engaging the teeth of a sector 15 rotatablymounted about a rock shaft 17 jour nailed in the bracket. At an oppositeend of the bracket there is journalled a rock shaft 19 having arms 21and 23 secured thereto.' Secured to shaft 17 is an arm Q5 and a linlr27connects arms 21 and S25. The sector 15 eX- teni below the shaft 17having the form of a Luvnward-ly directed arm 29. Between arm and arm 23mounted the fluidpressure & ier r31, the cylinder' being connected toIin'aciret by `fastening means 33. A tuiiston rod 34 projects throughAthe in* .l head 35 of the cylinder 31 and is contedio artic A. tubularvalve rod 86 through the removable head 37 at.- "i to the cylinder byfastening means 39 a ed 'tc arm The sector is itops projecting in spacedThe power'cylinde'r 31 conta1ns a, hollow( pistonl represented bynumerall 45. This piston is formed by a barrel 47 with c nd iianges 49and 51. Flange 51 is tapered to form a valve seat 53 and is provided.with an axial opening 55. Fastening means 57 serve to secure tovflange51 a piston header closure 59. This closure has a recess 61 and aconduit registering with opening 55.`v The conduit extends toward theremovable head;

37 and terminates in an axial bore v.65.provided in the stem portion ofthe iston closure. This extended end of the piston head or closurepasses through the removable head 37 and surrounds the valve rod 36mentioned above. The closure also has an opening 60 alfordingcommunication between the recess 61 and the adjacent end of thecylinder. `At the other en d of the piston there is an annular valveseat 67 and a'closure head 69 the seat 67 and the head 69 being held inplace by bolts 70. The'closure 69 is formed withv a recess municationbetween recess 71 and the end of the cylinder. Beyond the .recessedportion of the head, itis reduced in diameter to form the hollow pistonrod 34 referred to above, which piston rod extends through the cylinderhead 35 and is connected to arm 23. Within the hollow piston there areopposed valves 75 and 77. These valves are seated against valve seats 67and 53. They are normally held so seated by a common spring 79. Thesevalves are provided with angularly related faces as shown to engage thevalve seats and, also, to engage other valve-members as explained below.The valvesare also provided with recesses for a purpose to Vbedescribed.

The valve rod 36 is tubular at each end, but between the tubular ends itis solid as shown '71 and with an. opening 73 affording coml 5 valve rodhas a threaded stem 83 for the at-l tachment of apipe to be connected tothe hi h pressure side of a fluid pressure pump. t the other side of theintermediate closure 82, the other tubular part is in communication 10by means of openings 87 with the recesses 80 of the valves.- The valverod has secured thereto, or integral therewith, valves 89 and 91. Thevalves 89 and 91 are so spaced that when the valves 75 and 77 engagetheir seats carried by the piston they also engage the valves carried bthe valve rod, as well shown by Figure 2. T e Valve rod is arranged toreciprocate through the tubular portions of both piston end closures. Itterminates short of the' outer attached end of the piston rod 34. Thetubular opening of the piston rod 34 is in free communication with thetubular valve rod as shown in the drawings. The piston rod 311 has alsoa threaded stem 95 for the attachment of a pipe to be connected to thelow pressure side of the pump.- Since the pump vention, and since anyiuid pressure pump may be used, it has not been thought necessary toillustrate such a pump in connection with the invention. The operationof the device is as follows: The drawings 'show the parts at rest, aswhen the vehicle is moving straight ahead. When it is desired to turn,for the pur ose of steering the' hand wheel 3 is rotate as usual. In soturning the wheel the worm 13 rotates the freely mounted sector and itsarm 29. The arm 29 moves the valve rod 36 either inwardly or outwardlydepending upon the direction of rotation oi wheel 3. If the rotation issuch as to thrust the valve rod inwardly, the valve 89 pushes valve 77oli' its seat. Fluid under pressure from the pum is then free to flowinto opening 83, throng the hollow valve rod, through conduit 63 intothe hollow piston 45, out between valve 77 and its seat 53, through therecess 61 and out through opening into the adjacent cyl- 50 inder end.This pressure is then effective to move the piston to the left (Figure2). At-

the same' time, valve .'member 91 has been I moved to the left of thevalve 75, which con- .tinues to seat on valve seat 67 Fluid in the 55-adjacent end of the cylinder may then pass through opening 73, recess?1, between valve 91 and valve 75 into recess 8O and through opening 87out through bthe tubular end of '.-the valve rod and the piston rod,returning 5 to the pump by passage 95. No resistance is,

does not constitute a part of the inhicle in an obvious manner. Iftherotation of wheel 3 is stop ed, the valve rod 36 also ceases to movean the pressure of the fluid 4 of the cylinder. At the same time, thepresf sure at the right of the piston is relieved by the openinr of thevalve 89 from its seat on valve 77. he fluid at the ri ht of theoylinderescapes from recessSO t rough opening 87 and out through the powerpiston rod as before.

In the event that the fluid pressure .eans fails, the movement of thesect'or is effective to apply the steering gear by manual effort solelythrough the engagement of stops 41 with the arm 25.

I claim:

1. A fluid pressure device comprising a cylinder, a hollow piston havingopposed valve seats, means to conduct fluid under pressure to the spacewithin said piston and between said valve seats, said piston beingrecipro- 'Cable within said cylinder, a. piston rod connected to saidpiston and projected through one end of the cylinder, connections fromsaid rod whereby movement of said piston may perform work, a Valve rodreciprocable through the opposite end of said cylinder and alsoreciprocable through said piston, valves rigid with said rod, valveswithin said piston and seating against said rod valves and movablethereby, and also seated against the piston valve seats, yielding meansbetween said last-named valves, whereby reciprocation of said valve rodin either direction opens a valve to permit the fluid under pressure toUit pass from within the piston to one end of 'the cylinder and wherebysaid movement opens another valve to permit the relief of pressure sinthe other end of the cylinder.

2. 'In combination, a Acylinder with closed ends, a hollow pistonreciprocable therein, a tubular piston rod rigid with the piston andreciprocable through one end of the cylinders, connectionsfrom said rod.whereby movement oli-said piston i may'perform work, a valve rod-havingtubular ends and an intermediate solid portion,- said valve rodbeingreciprocable through the other end of the cylinder, through the hollowpiston and vslidably guided within the piston rod, connections wherebythe tubularv portions of the valve rodvmay beconnected respectively to al I high pressure and a low pressure side of a source of fluidpressure,means comprlsing a conduit whereby the high pressure tube ofthe valve rod is in communication withl the interior of the hollowpiston, opposed valves in-said pistons, said valves surrounding andcapable of movement by said valve rod to admit fluid pressure fromWithin said piston i to one of the cylinder ends and to simultaneouslypermit the escape of fluid pressure from the other side.

3. In a power operating mechanism, a rock shaft, an arm rigid therewithfor performing work, a second arm rigid with said shaft, a parallelshaft, oppositely directed arms on ature.

said parallel shaft, a link connecting the secv ond arm of the iirstshaft with one of the arms of the parallel shaft, a power cylinder fixedin position, a piston in said cylinder, a piston rod extending therefromand connected to the other arm of the parallel shaft, a valve rodreciprocable in said power c linder to renderl said-'power cylinderoperab e upon the rock shaft in either direction of reciprocation, asector rotatable on said rock shaft, manually operable means operablyconnected to rotate said sector, and a connection from said sector tosaid valve rod whereby the actuation of said manually operable meansrenders the power cylinder operative in either direction of rotation ofsaid manually operable means.

4. Power operating mechanism comprising parallel shafts, a rigid arm onthe irst one of said shafts, means whereby rotation of said first shaftperforms work, a lever rotatably mounted on said-first shaft, manuallyoperable means to rotate said lever, a lever fixed to said second shaft,link connection between said lixed lever and the fixed arm on the firstshaft whereby the .rotation of the second shaft rotates the rstshaft,power operated mechanism, connections therefrom to both said xed leverand said rotatable lever,

' valve mechanism associated with said power operated mechanism, one ofsaid connections operable upon said valve mechanism whereby the poweroperated mechanism `rotates said fixed lever.

v5. The invention defined by claim 4, together with means to limit therotary movement of said manually f operable means relative to said firstmentioned shaft.

6. Power mechanism comprising parallel shafts, a rigid arm mounted on afirst one of said shafts, means whereby rotation of said first shaftmayperform work, a lever rotatably mounted on saidfirst shaft, manuallyoperable means to rotate said last-mentioned lever, a lever fixed to thesecond shaft, linkconnecting means between an arm of the lever xed tothe second shaft and the rigid arm on the first shaft whereby rotationof the second shaft rotates the first shaft, power operated mechanism.,connections therefrom to a second arm of the lever fixed to the secondshaft and to the rotatable lever on the first shaft, valve mechanismassociated with said power operated mechanism, one of said l flats 1

